Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Disruptive selection and the genetic basis of bill size polymorphism in the African finch Pyrenestes

Abstract

MECHANISMS producing and maintaining discrete polymorphisms have long fascinated evolutionary biologists1,2. Despite the ubiquity of non-sex-limited polymorphisms in vertebrates, the evolutionary factors maintaining them are well understood in only a few instances3. The African finch Pyrenestes is unique among birds in exhibiting a non-sex-determined polymorphism in bill size4,5. Morphs breed randomly with respect to bill size and differ in diet and feeding performance on soft and hard seeds4,6. I present here: (1) new data showing that the polymorphism appears to result from a single genetic factor; (2) support from long-term field studies for earlier suggestions that disruptive selection is acting on bill size; and (3) data revealing the presence of a possible third, much larger morph. Results suggest that the polymorphism may have arisen through single mutations, where morphs occupy distinct adaptive peaks through differences in feeding performance on seeds differing in hardness.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

References

  1. Mayr, E. Animal Species and Evolution (Harvard Univ. Press, Cambridge, 1963).

    Book  Google Scholar 

  2. Thoday, J. M. Nature 181, 112 (1958).

    Article  Google Scholar 

  3. Futuyma, D. J. Evolutionary Biology (Sinauer, Sunderland, MA, 1986).

    Google Scholar 

  4. Smith, T. B. Nature 329, 717–719 (1987).

    Article  ADS  Google Scholar 

  5. Smith, T. B. Biol. J. Linn. Soc. 41, 381–414 (1990).

    Article  Google Scholar 

  6. Smith, T. B. Ecology 71, 1246–1257 (1990).

    Article  Google Scholar 

  7. Smith, T. B. Oikos 60, 76–82 (1991).

    Article  Google Scholar 

  8. Smith, T. B. Evolution 44, 832–842 (1990).

    Article  Google Scholar 

  9. Schluter, D. Evolution 42, 849–861 (1988).

    Article  Google Scholar 

  10. Smith, T. B., Frampton, T. & Seibels, R. Proc. 1990 Regional AAZPA (1990).

  11. Smith, T. B. Proc. 8th Pan-African Ornithological Congr. (Bujumbura, Burundi, in the press).

  12. Orr, H. A. & Coyne, J. A. Am. Nat 140, 725–742 (1992).

    Article  CAS  Google Scholar 

  13. Charlesworth, B. & Charlesworth, D. J. theor. Biol. 55, 305–324 (1975).

    Article  CAS  Google Scholar 

  14. West-Eberhard, M. J. Proc. natn. Acad. Sci. U.S.A. 83, 1388–1392 (1986).

    Article  CAS  ADS  Google Scholar 

  15. Mayr, E. The Growth of Biological Thought (Harvard Univ. Press, Cambridge, 1982).

    Google Scholar 

  16. Fisher, R. A. The Genetical Theory of Natural Selection (Dover, New York, 1958).

    MATH  Google Scholar 

  17. Falconer, D. S. Introduction to Quantitative Genetics (Longman, London, 1981).

    Google Scholar 

  18. Meyer, A. Oecologia 80, 431–436 (1989).

    Article  CAS  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Smith, T. Disruptive selection and the genetic basis of bill size polymorphism in the African finch Pyrenestes. Nature 363, 618–620 (1993). https://doi.org/10.1038/363618a0

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/363618a0

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing